白三烯B4对人永生化角质形成细胞的影响

Effects of Leukotriene B4 on Immortal Keratinocytes

目的探讨白三烯B4(leukotriene B4,LTB4)对人永生化角质形成细胞(immortal keratinocytes,HaCaT细胞)的影响。方法将中波紫外线(ultraviolet B,UVB)和LTB4分别或共同作用于HaCaT细胞,观察端粒酶逆转录酶(human telomerase reverse transcriptase,hTERT)、细胞增殖指数(proliferation index,PI)及白三烯B4受体(leukotriene B4 receptor,BLT)的变化。分别采用流式细胞仪检测HaCaT细胞周期的变化,RT-PCR检测hTERT mRNA水平,同时采用免疫荧光结合激光共聚焦显微镜和Western-blot法检测BLT的表达。结果HaCaT细胞存在BLT表达,表达分布于胞膜和胞浆;UVB单次照射HaCaT细胞,BLT的表达升高(P<0.05),PI降低;LTB4使HaCaT细胞hTERT表达上调、PI增高,但BLT表达与空白对照组相似;UVB+LTB4共同作用于HaCaT细胞后,其PI下降,BLT、hTERT mRNA与空白对照组比较无显著性差异(P>0.05)。结论HaCaT细胞可表达BLT蛋白,LTB4能促进HaCaT细胞增殖,UVB照射可能促进HaCaT细胞BLT的表达。

Objective To investigate the effects of leukotriene B4 （LTB4） on immortal keratinocytes （HaCaT cell）. Methods After treated with ultraviolet B （UVB） and LTB4, alteration cell cycle was analyzed by flow cytometry. The mRNA level of human telomerase reverse transcriptase （hTERT） was detected by reverse transcriptase polymerase chain reaction （RT-PCR） and the expressions of leukotriene B4 receptor （BLT） in HaCaT cell were measured by immunofluorescence and immunoblotting respectively. Results It was shown that both BLT1 and BLT2 existed in HaCaT ceils, and distributed in cell membrane and cytoplasm. Higher expression of BLT in HaCaT ceils was induced by UVB single irradiation （P〈0.05）. However, proliferation index of HaCaT cells was decreased. LTB4 might up-regulate the mRNA expression of hTERT and the increase of proliferation index, but shown no effect on the expression of BLT in HaCaT cells compared to control ceils. Proliferation index of HaCaT cells treated with UVB and LTB4 was lower than that of control cells, while the mRNA expression of hTERT, BLT of HaCaT cells are no difference among the different groups （P 〉 0.05）. Conclusions It is shown that BLT1 and BLT2 exist in HaCaT ceils, and LTB4 can stimulate proliferation of HaCaT cells. Higher expression of BLT in HaCaT cells can be induced by UVB.